import { Injectable } from '@angular/core';
import { Subject, BehaviorSubject, Observable }  from 'rxjs';
import { HttpClient, HttpParams } from '@angular/common/http';
import { Order } from './order.model';
import { UserService } from '../user.service';
import { User } from '../user.model';
import { LineItem} from '../items/lineitem.model';

@Injectable({providedIn: 'root'})

export class OrderService {
	private dataStore: { total:number, user: User, order: Order } = {
		total: 0,
		user:{
			address: '',
			session: '',
			blocktime: 0
		},
		order: {
			address: '',
			session: '',
			timestamp: '',
			closed: false,
			lines: [
				{
					qty: 1,
					name: '',
					cost:0
				}
			]
		}
	};
	private _orderUpdated: BehaviorSubject<Order> = new BehaviorSubject(this.dataStore.order);
	public readonly orderUpdate: Observable<Order> = this._orderUpdated.asObservable();
	private _totalUpdated: BehaviorSubject<number> = new BehaviorSubject(this.dataStore.total);
	public readonly totalUpdate: Observable<number> = this._totalUpdated.asObservable();
	public userUpdate: Observable<User>;

	constructor(
		private http: HttpClient,
		public userService: UserService
	) {
		this.userUpdate = userService.userUpdate;
		this.userUpdate.subscribe((user) => {
			this.dataStore.user = user;
			//console.log('OS: const', user);
			this.getOrder();
		});
	}

	getOrder() {
		var session = this.dataStore.user.session;
		const params = new HttpParams().append('session', session);
		let obs = this.http.get<{message: string, order: any}>('http://localhost:3000/api/order', { headers:{}, params:params, observe: 'response'});

		obs.subscribe((OrderDataResponse) => {
			if (OrderDataResponse.status == 200) {
				this.dataStore.order = OrderDataResponse.body!.order;
				this._orderUpdated.next(Object.assign({}, this.dataStore).order);
				this.dataStore.total = 0;
				for(var line of this.dataStore.order.lines) {
					this.dataStore.total += line.qty * line.cost;
				}
				this._totalUpdated.next(Object.assign({}, this.dataStore).total);
			} else {
				console.log('No order found');
			}
		});

		return obs;
	}

	addToOrder(lineItem: LineItem) {
		if(this.dataStore.order._id != null) {
			let obs = this.http.post<{message: string}>('http://localhost:3000/api/lineitem', { order_id: this.dataStore.order._id, line: lineItem });
			obs.subscribe((orderData) => {
				this.getOrder();
			});
		} else {
			this.createOrder(lineItem);
		}
	}

	createOrder(lineItem: LineItem) {
		var order:Order = {
			address: this.dataStore.user.address,
			session: this.dataStore.user.session,
			closed: false,
			lines: []
		};
		let obs = this.http.post<{message: string, order: Order}>('http://localhost:3000/api/order', {order: order});
		obs.subscribe((orderData) => {
			console.log('Create order', orderData);
			this.dataStore.order = orderData.order;
			this._orderUpdated.next(Object.assign({}, this.dataStore).order);
			this.addToOrder(lineItem);
		});

		return obs;
	}

	cancelOrder(id: string) {
		let obs = this.http.delete<{message: string}>('http://localhost:3000/api/order/'+id);

		obs.subscribe((OrderResponse) => {
			console.log('Order deleted');
			//this.getOrder();
			this.dataStore.order = {
				address: '',
				session: '',
				timestamp: '',
				closed: false,
				lines: [
					{
						qty: 1,
						name: '',
						cost:0
					}
				]
			};
			this._orderUpdated.next(Object.assign({}, this.dataStore).order);
		});

		return obs;
	}

	closeOrder(){
		this.dataStore.order.closed = true;
		let obs = this.http.post<{message: string, order: Order}>('http://localhost:3000/api/order', {order: this.dataStore.order});
		obs.subscribe((orderData) => {
			console.log('Closed order', orderData);
			this.dataStore.order = {
				address: '',
				session: '',
				timestamp: '',
				closed: false,
				lines: [
					{
						qty: 1,
						name: '',
						cost:0
					}
				]
			};
			this._orderUpdated.next(Object.assign({}, this.dataStore).order);
		});

		return obs;
	}

}